Sodium chlorate (NaClO3) is a paper bleaching agent used in the pulp and paper industry. It is less harmful to the environment than chlorine gas and as a result, its demand has increased significantly during the years. It is produced in electrolysis cells and the global chemical reaction is:NaCl+3H2O→NaClO3+3H2 
The voltage between the electrodes of the electrochemical cells is typically between 3.0 and 3.2 volts for a current density of 250 mA/cm2. At the cathode where hydrogen is released, one often uses iron as electrode material. The cathodic overpotential for an iron electrode is about 900 mV. This high overpotential for the hydrogen evolution reaction constitutes the principal source of energy loss of the process of synthesis of sodium chlorate. In open circuit, the iron electrodes have also the tendency to corrode severely in the electrolyte therefore affecting their life span. For all of these reasons and considering the increase of energy costs, researchers have tried in the last few years to find substitutes for the iron electrode in order to improve the energy efficiency of cells for the synthesis of sodium chlorate.
One of these substitutes is described in the U.S. Pat. No. 5,662,834 and in the corresponding Canadian patent #2,154,428 who propose new alloys based on Ti, Ru, Fe and O and the electrode coatings based on these materials which allow to reduce the overpotential at the cathode by about 300 mV. However, these alloys are expensive because they require significant amounts of the catalytic species “ruthenium” (Ru) to be active. The international patent application PCT/CA2006/000003 and the corresponding Canadian application CA 2,492,128 try to solve this problem by proposing to replace part of the ruthenium by aluminum in materials similar to those of the patent U.S. Pat. No. 5,662,834 while preserving the beneficial catalytic properties. Therefore, these last patent applications propose alloys based on T, Ru, and Al with a reduced content of ruthenium which show cathodic overpotentials of about 600 mV similar to those of alloys based on Ti, Ru, Fe and O. These alloys have similar crystallographic structures of the cubic type β2 where the (000) site is occupied by Ti and the (½,½, ½) is occupied in one case, by a random mixture of Fe and Ru (U.S. Pat. No. 5,662,834) and in the other case, by a mixture of Al and Ru (PCT/CA2006/000003). The problem with these materials and this structure is that it absorbs hydrogen easily and this leads to its deterioration in time. Indeed, in order to reduce this hydrogen absorption tendency, it is necessary in all of these cases, to introduce oxygen or an element such as boron which makes the materials fragile and hard to fabricate as electrode coating. This tendency to absorb hydrogen is partly caused by the presence of Ti in the structure which forms strong chemical bonds with hydrogen. Therefore, it would be desirable to find a new structure without Ti which could host the catalytic specie, would not absorb hydrogen, and would show a low cathodic overpotential even when the catalytic specie is at low concentration.